Zymic

New document: 468 x 60 pixels. Fill canvas with colour #6aa02b

Make a new layer and make white your foreground colour.

Select the "Gradient tool" and select the "white > transparent" gradient as shown in the second picture.

Hold shift and drag from the top to just over a one 3rd of the document.

Set the layer mode to "Overlay"

Use the Elliptical Marquee Tool and make a curve edge on the far right side of the banner

Make a new layer and fill the selection in with white. Press CTRL+D to deselect.

Bring up the blending options.

> Outer Glow
> Bevel & Emboss
> Gradient Overlay

And now you should have:

Now select half of the current layer.

Make a new layer, fill the selection in with white and change the opacity to 17% This should give it a bit of a shine.

Now type the initials of your host name, for example purposes I did zh - zymichost and I used the font Dungeon (comes with XP)

Change the text colour to #2f2f2f

Use this blending style for stroke. (Click Here)

Make a selection like below. Make a new layer and drag it underneath all the other layers so it's all behind. Fill it in with white.

Now give the layer this stroke - click here

Now using the gradient tool make a gradient similar to below.

Insert an image of some servers, perhaps shadow it slightly.

Use the Rounded Reqtangle Tool and make a shape like below

Bring up the blending styles:
Inner Glow .. Click Here
Bevel & Emboss .. Click Here
Gradient Overlay .. Click Here

Now add some text and what your company offers. I added a few touches such as a border etc. Other Colours:
Blue
Red
Yellow